The story engraved on Stela 5 at Izapa is no more than a story and meaningless symbols, unless we can arrive at the point where we understand the mighty realities behind the symbols.
The circumstantial evidence of the mighty realities behind the symbols on Stela 5 is that Jesus is the Christ and that, in our journey through life, we may inherit eternal life by adhering to the teachings and ordinances of the gospel of Jesus Christ. That is the message of the tree-of-life as recorded in the early chapters of I Nephi.
Perhaps the real debate regarding Stela 5 is not if it can be determined intellectually to be an authentic sculpture associated with the vision of Lehi, but rather if it can be determined spiritually to have gospel truths represented in its symbolic engravings.
Symbols of Christ and eternal life seem to be adequately spelled out in symbols on the stone. The serpent, the fish, and the humming birds are all associated with Christ and eternal symbols of man's birth, death, and resurrection. The "U" glyph at the top of the panel may even represent the celestial kingdom.
Two fish are shown in the stone, with pieces of fruit in their mouths, signifying that if man partakes of the fruit of the tree-of-life, he will ascend into heaven. Two fish are also present at the top of the panel with their faces returning to earth, which may symbolize the resurrection of man.
Two humming birds have their beaks attached to the nostrils of the two-headed serpent. If the serpent is representative of Christ, then the two humming birds represent the gaining of eternal life through the nostrils of the serpent. It is strange, but very interesting, that humming birds attach their beaks to a tree during the winter months, lie in a state of hibernation, and appear as if they were dead. When spring arrives, life is restored to the humming birds, and they are reborn, or resurrected.